Vibrating apparatus and method for its utilization for removing patterns and castings from sand molds



March 5, 1929. Q B plKE 1,704,100

VIBRATING APPARATUS AND METHOD FOR ITs UTILIZATION FOP. REMOVINGPATTERNS AND CASTINGS FROM SAND MOLDs Filed Aug. 8, 1927 InventorPatented Mar. A', 1929.

Unirse i sra CLINTON B. PIKE, 0F .BRL'ENGHALL AIAIBAMA.r

VIBRATING APPARATUS AND Marston non irs u'rrnrzs'rron non nnivrovmePA.--

TERNS AND CASTINGS FRI-0M f lAllDy MOLDS.

Appli-cation filed August 8, i927. Serial No. 2411,395. 'y l Myinvention relates to a novel vibrating apparatus and to a method for itsuse to facilitate the removal of patterns and cast ings from sand molds.My invention is especially, though not exclusively, adapted for theremoval of patterns used for forming sand moldsfor hollow cylindricalcast metal bodies such as cast iron pipe and the like, and l contemplatethat it will prove etlicacious for freeing hollow castings, irrespectiveof their shape mold in which they were east and thereby facilitatingtheir removal. l

ris my invention in the form herein shown is more particularly directedto the centrif ugal cast pipe art wherein sand molds are employed, itsapplication to that will be more particularly7 described,r` withoutthereby intending to limit my invention to such particular use. y

In the present practiceof forming centrif ugal sand molds for pipe, thesand is rammed either by jolting or the pneumatic methods which resultin the packing or con pression of the sand by blows or motion in thedirection of the long axis'of the mold, and while this produces anexceedingly dense mold from which it is very diflicult to remove eitherthe pattern or the Finished cast,- ing, nevertheless I have found thatthe sand, even though thus densely packed, will readily yield,sufficiently lto loosen its grip on l the pattern, to torces appliedradially or transversely to the long axis of the pipe and it is thisslightradial or transverse compressing of the sand which my inventionmakes use of to free the vpattern or easing and permit its ready removalfrom the mold.

My invention contemplates the utilization of a rapidly rota-tingvibrator, preferably in' the form of a disk or cylindrical body mountedconcentrically on its drive shaft,y

which body is adapted, responsive to,cent-rif-V ngal or gyroscopicforces, to assume a worl ing position more or less out of line withtheaxis of the hollow body to be vibrated thereby and which is free to havea planetary motion within the vibrated element as it travels, responsiveto its rotating drive, in an orbit about the loiig axis of the hollowbody. As the vibrator moves with more or less frietional engagement withthe vibrated element it imparts thereto a rhythmieal vibrating oroscillatory Vmotion about its own long axis, said motion being in itsextent governed by or composition, from the sand structure ofthecasting.

various vfactors such as the vrelative diameters of ,the vibrator and ofthe interior of the element vibrated, ,theY eP. M. of the vibrator head,and its weight relativeto the weight or inertia of the element to bevibrated. y y .i

By my improved method and apparatus I amable to producevibrationsrepresenting in number multiples of the R. P. .M. of the vibrator andthese relatively short frequent impulses following the planetarymovement of the vibrat'ortend to move the vibrated body rhythmicallyabout its long axis, and actin a remarkably short time to `effect asutlicfient radial compression of the sand which will loosenthe patternor casting and facilitate its ready removal. kThis radial orlateral.compression of the sand in the mold needed to free the patternis very slight and 'it takes place with maximum uniformity throughoutthereby leaving the sand mold not only in ideal condition as to surfacecom'- pactnessfand smoothnessbut Valso Afree of any distortionthat mayeffect the uniform Obviously it is pos sible to free the pattern by aninfinitelyl small enlargement of the mold diameter as both sand mold andpattern are inelastic elements and yet an exceedingly small enlargementof the mold makes it possibleto free and remove the pattern or finished`casting from the mold with remarkable ease. At the present suchpatterns and casting are removed with the greatest l.diilicult boththepattern and the mold being subjected to very great forces in the effortto pull the pattern from the mold and it being usually necessary to cutaway the sand from about the; casting by augurs,

drills and the like.

Some of the more important advantages of my invention over previouspractice in the sand molding art are z-That the vibrating y element neednot be attached to the element vibratedand is thus freely` movableintoand out of operating relation therewith; it is free to co-actcircumferentially within the ele sent vibrated so as to work in alldirections radially against 'the sand; it feeds itself automaticallyabout the interior of the element vibrated and tends to cause alcylindrical element to follow it with a lag when loosened; it isadaptedto have ready relative adjustment lengthwiseof the elementvibrated, if v,such be necessary, so as to work at different pointslengthwise of the elongated vibrated element;

and it is susceptible of wide variation in structure, requiring only arotating vibrator head suitable to frictionally engage the innerperimeter of the element vibrated and having a flexible drive shaftwhich will permit it to follow a planetaryniotion while at work. l

With the above objects in view my invention consists in the device andin the process for utilizing it which is hereinafter,more particularlydescribed and claimed in typical embodiments thereof, reference beinghad to the accompanying drawings, in which F ig. 1 shows a verticalsection through a sand mold for the casting of centrifugal pipe havingtherein a hollow pattern with which a single vibrator is shown inco-operative relation.

Fig. 2 Shows a Vmodification of my invention, wherein a plurality ofvibrators are'carried by a flexible sectional shaft and adapted toco-.act at a plurality of points lengthwise of the element vibrated toimpart synchronous vibrations throughout its length.

Fig. 3 is a plan view of l, showing vibrator unbalanced.

Similar reference numerals refer to similar parts throughout thedrawings.

In the embodiment of my invention illustrated in Figs. l and 2, l show amold flask 5, suitable for receiving a cylindrical or hollow pattern 6,between which and the flask sand is rammed to form a mold i' by anysuitable mechanism which need not be described. The pattern shown is ofa straight cylindrical type for casting a cylindrical body such as apipe, tube or like hollow casting and therefore serves merely as aconventional illustration typical of any pattern or element to bevibrated. The interior of the pattern will be preferably cylindrical butthis is not essential. After such pattern has been set in place and thesand tightly rammed about it, it has proven difficult to remove it fromthe sand mold and to overcome this I propose to make use of themechanism which will now be described.

Above the mold l dispose a rotary motor or drive mea-ns 8, preferably anelectric motor, and in order to produce relative axial movement betweenthe motor and the flask l .provide as the simplest means an I-beam guide9 which is engaged by a slide bracket 10 carrying the motor andsupporting the motor with its shaft substantially concentric with thepattern. A shaft 1l driven by the motor is adapted to depend into thepattern and carries fast on its lower end a vibrator head 12, which canbe balanced or unbalanced on its shaft. flChis head can be made up inmany ways and will have a diameter less to the desired degree than thediameter of the pattern, and a weight which will be varied in accordancewith the duty required. As shown in Fig. l, the head comprises a metalcylinder 12 mounted concentrically in balanced relation on the shaft 1lbetween plates 13 which are secured by nuts 14 and overhang the cylinderso as t receive and hold in position between them an annular' tread eleAment l which can be of any material best suited for the dutycontemplated. Preferably.` the shaft 11 will provide suticient{lexibility for the head, as it is rapidly rotated, to move laterallyuntil its tread portion engages the inner circumferential wall of thepattern or element to be vibrated. A frictional engagement between thehead and pattern will result and will produce a planetary movement ofthe rotating head as it travels about the pattern. As the head moves itimparts lateral or radial vibrations to the pattern tending to cause theaxis of the pattern to move outwardly along a spiral path therebyeliecting a slight radial compression of the surrounding sand. Thenumber of rotations of the head in completing its orbit will bedetermined by the relation ofits circumference to the inner perimeter ofthe pattern or element vibrated and for each rotation of the head therewill be obtained a plurality of vibrations dependent on variousoperating conditions. By raising the head it can be caused to act on thepattern in various positionsv lengthwise thereof and as soon as thepattern is loosened at all, if it is cylindrical, it will tend to rotateand follow the head responsive to the frictional engagement therewith ofthe head, and when freed it can be stripped with ease.

lt will be seen that, as the head l2 is rapidly rotated, and is broughtinto frictional engagement with the wall the pattern 6, the innersurface of the pattern 6 serves as a track for the rotating head l2.Ordinarily, the head 12 is brought into frictional engagement with theinner surface ofthe pattern immediately upon starting the motor S, dueto its own centrifugal force. l have found, however, that it issometimes necessary,' in order to secure immediate frictionalengagement, to laterally displace the shaft sufficiently for the head tocome in contact with the inner surface of the cylinder. (hice incontact., the inner surface of the pattern serves-asa track or race forthe head l2 upon which it runs. As the head l2 runs about the innersurface of the pattern, it exerts a centrifugal force radially againstthe wall o the pattern which is represented by the following formula:

where il] represents the weight of the head in pounds, o the linearvelocity of the center of gravity of the head l2 and its connections infeet per second, g the constant 32.1711, and lt the radius or"revolution of the center of gravity in feet. This radially directedcontrifugal force serves to symmetrically comsoy pressthe sand about thepattern until the pattern loosened.`

In Fig. 2, i show the vibrator head with a hole Q?) to uuluilance it.Such unbalancinn` will not change the actionv above described but willchangjethe character of thevibra* tions. j f

ln Fig. 3 l. have shown a device adapt-cd tosimultaneously 'ibratc apattern. or` liuisl'ied casting at various levels, thusexpeditingthe-worlr of frceingthe pattern or rasting from the sand mold.Here the motor 8 issupported by a suitable adjustable support 16 and hasa shaft 17 connected by a flexible joint 1S to a shaft sectionjl)carrying,` a rotating vibrator' head 220. ln like manner the shaftsection 19 lis connected by a flexible joint lSivith a shaft section 2land it in turn by a flexible coupling 1S with shaft section 22, eachshaft section carrying its vibrator' 20. This device is lowered into thecylindrical pattern or iinished casting and rotated when it will havethe plam-taryv movement described, and by engagement with the -innerwalls with the pattern or casting; produce a multiplicity of radiallydirected vibrations and which will be represented by a high multiple ofthe rotation of the shaft itself and these will gradually act on thepattern or casting to radially compress the sand i'nold su'lliciently tofree the pattern or tasting from the sand and permit its ready removal.The effect produced by the rotating traveling head on the pattern orcasting may or may not be truly vibra'tory but certainly it causes sucha displacement of the element acted upon in all directions in the planeof the heads rotation that the sand is uniformly compressed on all sidesof the said element. The vibrator head shoivs here a tread l5 of suchcharacter that when the head is centrifugally disposed the frictionalengagement oY if the tread l5 with the vibrated element will cause thehead to travel about the inner peL rimeter of the. element Whatever itsshape and as it moves to cause the displacement of the element for thepurposes desired. The vibra-v tor must be subjected to centrifugalforceto cause it to perform its work, and this can be accon'iplished byits motion about an axis whether or not it be at the same time rotatedabout its own axis, and it can be designed as it swings around andfrictionally engages the Work to impart the desired vibration and motionthereto.

While l have shown my invention in but two forms, it will be obvious tothose skilled in the art that it is not so limited, but is susceptibleto various other changes and modifiations, without departing from thespirit thereof, and l desire. therefore, that only such limitationsshall be placed thereupon as are imposed by the prior art or as arespecilically set forth in the appended claims.

Having thus described my invention, what claimas new and desire tosecurezby Letters Patenhis f f l. In an apparatus of the characterdescribed, a vibrator, drive means therefor, and a hollow element havingits vinternal perimeter frictionally engaged by the driven vibratory toradially displace it.

2. l'n an apparatus of'tliocharacter described, a vibrator, idrive meanstherefor which displace it. responsive to centrifugal force, and ahollow elen'ientihaving its internal perimeter frietionally enga,red'byl rthe driven vibrator to Alaterally displace said ele ment andto cause progressive movement of the vibrator about theelenientsperimeter. y

'2"3. ln an apparatus of the character described, a vibrator, a flexibledrive sha'ft for rotating said vibrator and supporting it free Iorlateral displacement, and a hollow' element to be vibrated having' aninternal perimeter about which the vibrator progresses responsive tofriction and centrifugal force and which tends to be disposed in thedirection in which the eentrifugalforce is exerted thereon. i

l. Apparatus according to claim 3, in which the vibrator comprises aplurality of vibrator heads mounted in spaced relation along' said driveshaft.

5. ln a process for the loosening, free for removal, of patterns,castings and the like from sand molds, the step Which consists insubjecting thearticle to be removed to internal force exertedoutwardlyand progressively about its internal perimeter.

6. `The method of loosening; a hollow cylin-k drical pattern from a sandrmold Without distortion of the sand which comprises, subjectingtheinner urface ofthepatternv to a relatively high frequency radiallydirected vibratory force, said force acting circumferlli() entiallyaround the inner surface of the pattern. f

7. The method of loosening a hollow cylini drical pattern in a sand moldWithout distor' tion of the sand which comprises, subjecting the innersurface of the pattern to a relatively high frequency radially directedvibratory force, said force being distributed circumferentially andlongitudinally of the pattern. i

8. The method of looseninga cylindrical pattern. in a sand mold Withoutdistortion of the stand which comprises, symmetrically enlarging` thermold around therpattern by a relativelyhigh frequency vibratory forcedirected radially against the inner surface of the pattern.

9. The method of sand molding, which consists in compacting the sandabout a pattern to form the initial mold, then subjecting the pattern toa vibratory action applied substantially uniformly about it thereby tosymmetrically enlarge the mold sufficiently to release the pattern forready removal.

tern, a motor 'for driving the rotary member47 Y.Y und flexible meansconnecting the motor and rotary member. i

ll. in apparatus ttor loosening` a hollow eylinclriez l pattern from asand mold, a rotary member loosely fitting' Within the pattern. a motorfor driving the rotary member, flexible means Connecting the motor andthe rotary member, and means providing rela tive longitudinal movementof the rotary member and the pattern While rotating.

l2. In apparatus for loosening a hollow cylindrical pattern from va sandmold, a rotary member Within the pattern, a motor havine its axis ofrotation in axial alignment wir-li the pattern, and flexible drivingmeans connectingvthe motor and the rotary member.

13. In apparatus for loosening hollow Cylinders in saiclmolds, a rotarymember clisposed Within the hollow7 of the cylinder and adapted to trackaround the inner surfaee thereof, and means for driving the rotlfirymember. y

In testimony whereof I affix my signatiire.

CLINTON is. PIKE.

